1. Field of The Invention
The present invention relates generally to a process for measuring the concentration of a component in a body fluid, such as blood, urine or the like. More specifically, the invention relates to a process for measuring the concentration of a component, which is able to produce hydrogen peroxide in the presence of an oxidase, in a body fluid. Further specifically, the invention relates to a process for measuring the concentration of a component, such as glucose, uric acid or polyamine, which serves as a substrate for an oxidase to produce hydrogen peroxide in the present of the oxidase, in a body fluid.
2. Description of The Prior Art
As is well known, organic components, such as glucose, uric acid, polyamine or the like, exists in body fluids, such as urine, blood, blood serum, blood plasma, lymph, saliva, gastric juice or the like. In the case of healthy or normal organisms, the concentrations of these components are constant. On the other hand, in the case of an abnormal organism, they are changed. For the purpose of medical diagnosis, it is therefore very beneficial to be able to accurately determine the concentration of these components in body fluids.
In particular, a very small amount of glucose exists in body fluids, such as blood, urine or the like. In the case of healthy or normal organisms, the glucose in the body fluids exists exists in extremely small quantity. On the other hand, in the case of an abnormal organism, such as for example, a diabetic, the concentration of glucose increases markedly. For the purpose of medical diagnosis, it is therefore very beneficial to be able to determine the concentration of glucose in body fluids.
A process for determining the concentration of glucose by using the reducing power of glucose is known. In this process, complicated operations must be performed, and highly precise measurements can not be obtained since the specificity thereof is low.
In a recently developed process, the amount of hydrogen peroxide produced in a reaction between glucose and glucose oxidase is used to determine the glucose concentration. In this process, after glucose oxidase is added to a sample of a body fluid, the amount of hydrogen peroxide produced by the reaction between the glucose and glucose oxidase is determined by way of chemiluminescence method, and thereafter the concentration of glucose can be obtained from a previously made calibration curve representing the relationship between the glucose and hydrogen peroxide.
However, since normally a small amount of hydrogen peroxide already exists in body fluids, such as urine, it is difficult to accurately determine the concentration of glucose by determining that of hydrogen peroxide when the concentration of glucose in the urine is very small, i.e. less than 10.sup.-4 mol/l.
Furthermore, it is known that a small amount of uric acid also exists in body fluids, such as blood, urine or the like, and that the concentration of uric acid in blood decreases in the case of renoprival hypergia, gout, diabetes, carcinomatous neoplasm, eclampsia, incipient peripneumonia, enteropathy, metal intoxication, hypertension and so forth, and that the concentration of uric acid in urine increases in the case of leukosis, grave hepatopathy, gout and so forth. Accordingly, it is very beneficial to determine the concentration of uric acid in body fluids in diagnoses of the aforementioned diseases or the like. In clinical medicine, various methods have been used in order to determine the concentration of uric acid in blood and urine. However, in conventional methods, it is difficult to accurately, simply and promptly determine the concentration of uric acid.
In addition, a very small amount of polyamine also exists in urine. In healthy organisms, the polyamine concentration in the urine is extremely small. On the other hand, in the case of a cancer patient, the amount of polyamine increases markedly. It is therefore very beneficial, in diagnosing cancer patients and so forth, to determine the concentration of polyamine in urine.
In order to determine the concentration of polyamine in urine, electrophoresis method, thin-layar chromatography, analysis of amino acid, gas chromatography, high-speed fluid chromatography and so forth have been used. In these methods, there are problems in that complicated operations, and a long time for measurement and preprocessing are required, and many samples can not be measured at once.
In a recently developed method, after a deacetylation enzyme which can convert an acetylplyamine in urine into polyamine, the concentration of polyamine in the urine is measured by using a simple absorptiometry. However, this method is not simple, since centrifugation and other complicated operations in which, after polyamine is absorbed into a cation exchange resin, the resin is washed with water and a desorption solution to be neutralized are required, and a long time is also required for coloring.
It is therefore a principal object of the present invention to provide a process for simply and quickly measuring the concentration of a component in a body fluid, such as blood, urine or the like.
It is a particular object of the present invention to provide a process for accurately determining the concentration of a component, which produces hydrogen peroxide in the presence of an oxidase, in a body fluid.
It is another object of the present invention to provide a process for accurately determining the concentration of components, such as glucose, uric acid and polyamine, in a body fluid.
Further objects and advantage will appear hereinbelow.